Firing mechanism for double-barrelled shotguns



May 20, 1969 E. P. SIMMQNS 3,444,640

FIRING MECHANISM FOR DOUBLE-BARRELLED SHOTGUNS 74 g jig. .7 75W INVENTOR.

fraai# A .50mm/7J BMJ, 4MM

Afm/way- 20, 1969 E. P. SIMMONS 3,444,640

FIRING MECHANISM FOR DOUBLE-BARRELLED SHOTGUNS Filed July 19, 1967 sheet Z of 2 I N VEN TOR.

3,444,640 FIRING MECHANISM FOR DOUBLE-BARRELLED SHOTGUNS Ernest P. Simmons, 1000 Sheridan Place, Olathe, Kans. 66061 Filed July 19, 1967, Ser. No. 654,431 Int. Cl. F41c 7/00, 11/10 U.S. Cl. 42-42 2 Claims ABSTRACT OF THE DISCLOSURE This application discloses a mechanism whereby both barrels of a double-barrelled shotgun may be fired `by successive pulls of a single trigger. It includes a connector extending from the trigger selectively to either of the two sears, said connector :being operable on the first pull of the trigger to release one of said sears, and upon release thereof from said first sear to automatically engage the second sear, and means for effecting release of the connector from the first sear when that sear releases the hammer associated therewith. The releasing means constitutes a member operable to apply a yieldable spring pressure biasing the connector to its disconnected position, but insufficient to effect said disconnection as long as the associated sear is engaged, and its movement resisted, by the hammer engaged thereby. However, when said hammer is released and its sear relieved of its pressure to ease the disconnecting movement of the connector, the spring pressure of the releasing means effects instantaneous disconnection.

This invention relates to new and useful improvements in firearms, and relates particularly to the firing mechanism of double-barrel guns whereby the barrels may be fired in sequence by successive pulls of a single trigger.

In firearms of this type there are necessarily two hammers, and two sears for holding the hammers in their cocked positions. The sear tripping connector which is disposed ybetween the sears and the single trigger must of course first engage only one of the sears, and after the hammer associated with that sear has been released, must be automatically shifted into operative engagement with the other sear, so that the next pull of the trigger will release the second hammer and fire the second barrel. Various arrangements have been proposed for accomplishing this shifting of the connector for engagement with the second sear, but most of these arrangements within my knowledge rely in one way or another on the recoil of the gun after the first barrel is fired, or the [rebound of the gun after said recoil, as by mounting a weight movably in the mechanism which, by its inertia, will perform the shifting of the connector during recoil or rebound of the gun. These arrangements, while satisfactory under normal conditions, are subject to certain disadvantages. For example, they are effective only on guns of sufficiently large bore to provide sufficient recoil or rebound force to operate the connector shifting mechanism positively. They are generally unsatisfactory on small caliber weapons. Also, in the event that the round of ammunition in the first barrel to be fired is a dud, or fires only imperfectly, the connector shifting mechanism will of course not be operated, and the shooter loses the second shot. This is naturally a serious disadvantage under many circumstances.

Various types of cam devices, such as that shown in my own prior Patent No. 2,711,042, issued lune 2l, 1953, have been tried in further effort to solve the problem. Generally, they utilize a cam member fixed to a sear or other portion of the gun mechanism, operable by 3,444,640 Patented May 20, 1969 ice movement of the trigger to cam the connector out of engagement with the rst sear to be tripped thereby, but not until after said sear has released its associated hammer. In other words, the cam must operate to disconnect the connector from the sear in response to the residual movement of the trigger which may 4be available after it has been moved far enough to trip the associated sear. This residual movement is often extremely slight, and the resulting necessity of extremely accurate adjustment of the cam members has pointed up a general defect of this type of operation. Namely, if the cam operates prematurely, it may effect disconnection before the associated sear is tripped, and both shots are lost, while if the cam operates a little late, it may not effect disconnection at all within the available residual trigger movement, and the second shot is lost. This extremely accurate cam adjustment is difficult to provide and maintain, being affected by normal wear of interengaging cam elements, and by possible bending, indentation or other deformation of elements which can easily occur in normal gun usage.

Accordingly the principal object of the present invention is the provision of a gun firing mechanism which obviates all of the above enumerated problems. While generally of the cam type mentioned, so as not to be dependent in any way on the recoil or rebound of the gun to effect disconnection and shifting of the connector between shots, the cam action in no way depends on completion of residual movement of the trigger after the first sear has been tripped. Generally, this object is accomplished by the provision of a connector release spring operable during initial movement of the trigger, but before the sear is tripped, to bias the connector yieldably in a direction to release it from the sear, but not with sufficient force to disconnect it from the sear so long as its movement is resisted by the frictional drag of the sear thereon, and so long as this drag is increased by resistance of the hammer to movement of the sear. However, when the hammer is released, the drag of the sear on the connector is correspondingly reduced so that the release spring affects instantaneous disconnection of the connector, even if the trigger is moved no further.

Another object is the provision of a connector shifting device of the character described which may be applied to present guns of the recoilor rebound-operated type, and which when so applied does not require any additional moving parts, and which may be used either as a supplement to or independently of the recoilor rebound-operated mechanisms of said present guns.

A further object is the provision of a connector shifting mechanism of the class described having a selector feature by means of which either barrel of a double-barrel gun may be fired first.

Other objects are simplicity and economy of construction, and dependability and positive operation under any and all conditions.

With these objects in view, as well `as other objects -which will appear in the course of the specification, reference will be had to the drawing, wherein:

FIG. l is a -side elevational view, with parts broken away, of the frame portion of a double-barrel gun, including a firing mechanism embodying the present invention, with both hammers cocked and with the connector positioned in operative relationship to one of the sears,

FIGS. 2, 3, 4, and 5 are enlarged fragmentary views similar to FIG. 1, showing sequentially the relative positions of the parts at the instant of release of the first hammer, after the connector has been disconnected from said first sear, after the trigger has been released and the connector engaged with the second sear, and at the instant of release of the second hammer,

FIG. 6 is an enlarged fragmentary sectional view taken on line Vl-VI of FIG. 1,

FIG. 7 is .an enlarged sectional View taken on line VII-VII of FIG. 1,

FIG. 8 is an enlarged fragmentary sectional view taken on line VIII-VIII of FIG. 1,

FIG. 9 is an enlarged fragmentary sectional view taken on line IX-IX of FIG. 2, `and FIG. 10 is an enlarged fragmentary sectional view taken on line X-X of FIG. 2.

Like reference numerals apply to similar parts throughout the several views, and the numeral 2 applies to the frame portion of a gun, only a part thereof being shown as it may be of any suitable construction. The forward end thereof is to the left as viewed in FIG. l, and the rearward end to the right. Said frame includes a body portion 4, a rearwardly extending upper tang piece 6, a rearwardly extending lower tang piece 8 spaced below said upper tan-g piece, and a rear tang piece 10E extending between and joining the rearward end portions of said upper and lower tang pieces.

The firing mechanism is contained principally in the open space bounded by body 4 and tang pieces 6, 8, and 10. 'It includes a left hammer 12 pivoted in lthe frame at 14 and urged forwardly by a strong leaf spring 16 to operate a firing pin 18 in the usual manner to detonate a shell 20 in one barrel 22, of the gun, and a right hammer 24 pivoted in the frame at 26 and urged forwardly by a strong leaf spring 28 to operate a firing pin 30 to detonate a shell 32 in the other barrel 34 of the gun, all in a manner well known in the art. The gun shown is of the over-and-under type, but it will be apparent that the invention could be `applied as well to guns wherein the barrels are disposed side-by-side.

A left sear 316 and a right sear 38 are disposed side-byside transversely of the frame just rearwardly of the hammers, being carried for independent pivotal movement by a common transverse pivot pin 40 in upper tang piece 6. Sear 36 has a tooth 42 engageable in a notch 44 of hammer 12 to hold said hammer in a cocked position against Spring 16, and sear 38 has a notch 46 engageable with a tooth 4-8 of hammer 24 to hold said hammer in a cocked position against spring 28. Said sears are prowided respectively with rearwardly extending tailpieces 50 and 52 adapted to cooperate with the Sear tripping connector as hereinafter described. Each sear is resiliently biased toward its hammer engaging position by a spring loaded plunger 54 carried thereby rearwardly of pivot 40 and engaging the lower side of upper tang piece 6, whereby the sear is urged downwardly and forwardly. The forward movement of each sear is limited by a toe `56 thereof and operable to engage tang piece 6 as hereinafter described. The gun is cocked by pivoting the hammers rearwardly by any suitable means, not shown, until the notch 44 and tooth 48 thereof are engaged by tooth 42 and notch 46 of the sears, respectively.

Associated with the sears is a connector 58 the upper end portion of which is disposed immediately to the rear of tailpieces 50` and 52 of the sears. On its forward face said connector is provided with a forward upwardly facing shoulder `60 and a pair of upwardly facing side shoulders 62 and 64. Said side shoulders are disposed respectively ,at transversely opposite sides of shoulder 60, and spaced rearwardly therefrom. Said connector is provided with a forward face 66 rising directly from the rearward edge of shoulder 60 and coincident with the forward edges of shoulders 62 and 64.

Lower tang piece 8 is longitudinally slotted intermediate its ends to receive a trigger 68, Isaid trigger being pivotally mounted therein at 70 and extending rearwardly and downwardly therefrom. The body portion of said trigger is provided with a substantially horizontal longitudindinal bore in which a plunger 72 is mounted for longitudinal sliding .and oscillatory rotary movement. A compression spring 74 is mounted in said bore between ,4 the forward end of the plunger and the closed forward end of the bore, whereby said plunger is urged rearwardly. Said bore is slotted along its upper edge, the trigger having side walls '76 rising therefrom, as best shown in FIGS. 6 and 7, and the rearward end portion of plunger 72 has a bifurcation 78 formed therein. The lower end of connector 58 extends into said bifurcation, and is secured in said plunger by means of a pivot pin which is transverse to the axis of the plunger. The connector is thus mounted for universal pivotal movement in the trigger, whereby shoulder 60` of said connector may be moved transversely to a position beneath the tailpiece of either sear. A pin 82 extends transversely between and is rigidly fixed in side walls 76 of the trigger, and the rearward edge of the connector is urged rearwardly thereagainst by spring 74. Said pin acts as a fulcrum, whereby the upper end portion of the connector is urged forwardly against the tailpieces 50 and 52 of the sears.

An inertia 'block 84 is mounted on the rearward face of connector 58 at the upper end thereof. It may be secured to the connector by any suitable means. The upper edge of said block, which is approximately parallel to and spaced below upper tang piece 6, has a slot 86 formed longitudinally therein, the block forming a shoulder 88 therein at the rearward end of said slot.

The connector 58 is shiftable transversely and longitudinally of the frame by a selector mechanism best shown in FIGS. 1, 9, and 10. A longitudinally extending slot 90 is formed through tang piece 6 above and to the rear of inertia block 84. Disposed within said slot for sliding movement forwardly and rearwardly is a substantially rectilinear block 92. A selector plate 94 is disposed against t-he outer surface of tang piece 6, and has a pair of spaced apart fingers 96 and 98 rigidly fixed thereto and depending therefrom into slot 90. Said lingers are disposed respectively in front of and behind 'block 92, and `are in frictional engagement therewith. Finger 96 extends below tang piece 6, and enters slot 86 of inertia block 84. Slot 90 is provided at its forward end with an inwardly projecting tongue 100, forming a notch 102 at the left side thereof and a notch 104 at the right side thereof. Plate 94 is provided on its upper surface with a thumb piece 106 by means of which the selector may be manipulated. Said selector is held in position by a leaf spring 108 bearing against the lower surface of tang piece 6 and having an aperture 110 formed therein in which the selector arm is secured for transverse sliding movement. At its rearward end spring 108 forms a detent 112 adapted, as the selector is moved forwardly and rearwardly relative to the frame, to engage releasably in either a forward notch 114 or a rearward notch 116, said notches Ibeing formed in the lower face of tang piece 6.

When the selector is positioned as shown, with finger 96 thereof in notch 102 and detent 112 in forward notch 114, finger 96 positions the connector transversely of the frame so that connector shoulder 60 is disposed behind left sear 36, and the connector is urged forwardly by trigger spring 74 to position said shoulder beneath the tailpiece of said left Sear. When the selector is moved rearward to engage detent 112 in notch 116, finger 96 thereof engages shoulder -88 of inertia block slot 86 and moves the connector rearwardly to a position entirely clear from the sears. This is the safety position. The selector plate may then 'be moved to the right until finger 96 is behind tang notch 104, then moved forwardly to move said finger into said notch. Connector shoulder 60 will then be disposed in operative position beneath the tailpiece of right sear 38.

The structure thus far described is old and well known in the art. My invention consists of notching the forward edge of connector 58 at 118, below the level of shoulder 60, the lower portion of said notch forming a cam surface as will be described, and the addition thereto of a cam release spring 122 to cooperate with said sam surface. Said cam release spring consists of a single length of spring wire bent in a general U-shape, having parallel legs 124 and a connecting portion 126. The free end portions of legs 124 are inserted slidably in bores 128 provided therefor in rear tank piece 10, and adjustably secured therein by a set screw 130 threaded in said tang piece and engaging one of said legs. Said legs extend forwardly from tang piece respectively past opposite sides of connector 58, so as to dispose connecting portion 126 in a horizontal transverse position just forwardly of said connector, generally within notch 118 thereof. Legs 124 are spaced suiciently far apart as not to interfere with the transverse shifting of the connector by selector plate 94.

The operation of the ring mechanism is substantially as follows. Assuming that the gun is cocked and the selector positioned as shown in the drawings, connector shoulder 60 is disposed 'beneath the tailpiece 50 of left sear 36, and the connector is urged forwardly against said tailpiece by trigger spring 74. Face 66 of the connector engages the tailpiece of sear 36, preventing connector side shoulder 64 from passing beneath the tailpiece of right Sear 38. It will be noted that the transverse width of connector shoulder 60 is less than the spacing between the tailpieces, so that said shoulder 60 can in no event engage both sears simultaneously. This prevents accidental simultaneous discharge of both barrels.

As the user pulls the trigger for the rst shot, the trigger elevates connector 58, forcing shoulder 60 upwardly against the tailpiece 50 of sear 36, pivoting said sear upwardly and elevating tooth 42 thereof out of engagement with sear notch 44, thus releasing left hammer 12 and firing one barrel of the gun. FIG. 2 shows the position of the parts at the instant of release of hammer 12. During this releasing motion of sear 36, the cam surface 120 of notch 118 of the connector is elevated and engages connecting portion 126 of cam release spring 122, and flexes said spring upwardly, also as shown in FIG. 2. The spring, acting on cam surface 120, thus biases connector 5S pivotally to the rear against the pressure of trigger spring 74, with a force stronger than that of said trigger spring. However, the connector cannot immediately move to the rear, due to the frictional drag of sear tailpiece 50 on shoulder 60 thereof. This drag is substantial until hammer 12 is released, since hammer spring 16 is quite strong and the engagement of hammer notch 44 with sear tooth 42 therefore imposes substantially resistance to movement of the sear, so that connector shoulder 60 must exert substantial upward force on tailpiece 50, and there is substantial friction therebetween. However, at the instant hammer 12 is released by the sear, nearly all resistance to upward movement of tailpiece 50 is removed, the frictional drag between said tailpiece and shoulder 60 is relieved and the connector can be moved rearwardly with ease. Cam release spring 122 then is free to recover to move its connecting portion 126 downwardly, and in so doing slides along cam surface 120 of the connector to pivot said connector rearwardly, as shown in FIG. 3. It will of course be apparent that the hammer must be released before shoulder 60 is cammed out of engagement with the sear tailpiece, since otherwise the gun would not re at all. In previous mechanisms using iixed or rigid cams to move the connector, difiiculty has been experienced in maintaining the cam in suiciently accurate adjustment to provide the proper sequence of hammer and connector release within the limited movement of the trigger. The problem does not exist with the present structure however, since the spring 122 applies a biasing force to the connector immediately, but cannot move it till the hammer is released. Thus the connector cannot be disconnected prematurely before the hammer is released, the release of the hammer actually being the operation which triggers the disconnection of the connector. Moreover, once the hammer is released, rearward disconnecting movement of the connector is automatic and immediate, not relying on further residual movement of the trigger. Another problem of mechanisms using fixed cams has been maintaining the cam with suicient accuracy to provide positive disconnection of the connector during the often extremely slight residual or overtravel movement of the trigger still available after the hammer is released. The present invention also solves that problem. Also, the sensitivity or force of spring 122 is not particularly critical, since the frictional drag on shoulder 60 is substantial before the hammer is released, and virtually non-existent after the hammer is released. Thus it is necessary only that spring .portion 126 engage and be moved to almost any degree by cam surface of the connector, the degree of movement being largely immaterial, as almost any force applied thereby will disconnect the connector once the hammer is released. Such adjustment of spring 122 as may be necessary can be formed easily by loosening set screw 130.

After hammer 12 is released and connector shoulder 60 is moved rearwardly by spring 122, sear 36 is pivoted downwardly and forwardly by its associated spring plunger 54 to the position shown in FIGS. 3-5, said movement being limited by the engagement of sear toe 56 with upper tang piece 6, and connector 58 is urged forwardly by spring 74 against cam spring portion 126. The parts then have the position shown in FIG. 3. When the user releases trigger 68, connector 58 is lowered to allow cam spring portion 126 to enter notch 118 thereof, and spring 74 urges said connector still further forwardly to engage shoulder 64 thereof beneath tailpiece 52 of right sear 38, the parts then having the position shown in FIG. 4. The connector is disposed a little farther forwardly than before the firing of the first barrel, as may be seen from a comparison of FIGS. 1 and 4, but connector notch 118 is deep enough to accommodate portion 126 of the release spring.

On the next successive pull of the trigger, therefore, connecter shoulder 64 will elevative tailpiece 52 of right Sear 38 to remove notch 46 of said sear from engagement with tooth 48 of right hammer 24 to re the second barrel of the gun. FIG. 5 shows the position of the parts at the instant of release of hammer 24. During this second pull of the trigger, cam release spring 122 is again flexed by engagement of portion 126` thereof with cam surface 120 of the connector, and said spring will therefore again pivot the connector rearwardly to disengage it from sear 38. However, this disengagement is largely immaterial, since after both barrels have been fired no malfunction can result if the connector does not disengage from the sears. If the selector 94 is moved rearwardly, to the right, then forwardly, `as previously described, connector shoulder 60` will be disposed beneath the tailpiece 52 of sear 38, and connector shoulder 62 will be disposed irn- -mediately behind tailpiece 50 of sear 36. When the parts are so set, and the hammers cocked, the tiring operation is substantially the same as previously described except that sear 38 and right hammer 24 are actuated on the first trigger pull by connector shoulder 60, and sear 36 and left hammer 12 are actuated on the second trigger pull by connector shoulder 62.

Inertia block 84 is used in many presently existing guns, and has approximately the same function as sear cam release spring 122. That is, after the lirst barrel of the gun is red, and after the subsequent recoil of the gun, the gun rebounds forwardly, whereupon inertia will cause block 84 to move rear wardly with respect to the sears, thereby disengaging it from the sear related with the barrel just fired, yand permitting said sear to be pivoted forwardly. As has been pointed out, however, the inertia block operation is unsatisfactory in small bore guns, as the rebound force is not sufficient to provide positive operation, or where the ammunition in the rst barrel to be red is a dud, or fires imperfectly. It is evident that the addition of spring 122 may be accomplished without removing the block or otherwise altering the mechanism.

It is also evident, however, that the addition of the spring provides a more satisfactory positive mechanical action than the inertia operation, and that the inertia block may thus be dispensed with if desired.

What I claim as new and desire to protect by Letters Patent is:

1. In a double-barrelled shotgun, the combination of (a) a frame,

(b) a pair of hammers carried by said frame and associated with the respective barrels of said gun, and each operable upon release from a cocked position to lire a shell in the associated barrel,

(c) a pair of sears carried by said frame each being loperable to secure one of said hammers releasably in its cocked position, and being releasably by upward movement of a rearwardly extending tailpiece thereof to release the associated hammer, said tailpieces being disposed in side-by-side relation,

(d) a trigger pivoted in said frame below said tailpieces for vertical upward movement,

(e) an elongated connector pivoted at its lower end to said trigger and having its upper end disposed behind said tailpieces, said connetcor having an upwardly facing forward shoulder engageable beneath one of said tailpieces and a transversely offset upwardly facing rearward shoulder engageable beneath the other of said tailpieces,

(f) means urging said connector forwardly whereby to urge the forward shoulder thereof into operative engagement beneath the rst of said tailpieces, said engagement normally holding the rearward shoulder out of engagement with the second of said tailpieces,

(g) a yieldable cam release member carried by said frame and operable to engage said connector as the latter is elevated by said trigger, whereby to apply to said connector a biasing force tending to move said connector rearwardly to disengage it from said first tailpiece,

said force being insufficient to effect disengagement so long as the resistance to movement of the associated sear caused by engagement thereof with its associated hammer produces a substantial frictional drag between said forward shoulder and said rst tailpiece, but sufficient to effect disengagement when said frictional drag is reduced by release of the associated hammer, said connector having a cam surface inclined downwardly and forwardly beneath the level of the shoulders thereof, said cam release member including a cam element carried by said frame and disposed above said cam surface, whereby to be engaged by said cam surface as the connector is elevated by said trigger, said cam element being resiliently supported for yieldable vertical deflection, and

(h) means whereby said cam element may be adjusted forwardly and rearwardly in said frame whereby to adjust its position relative to the cam surf-ace of said connector.

2. The combination as recited in claim 1 wherein said frame includes a rigid portion spaced rearwardly from said connector, and wherein said cam release member constitutes a length of spring wire formed in U-shape to provide a pair of generally parallel legs secured at their free end portions in said rigid frame portion and extending forwardly therefrom respectively at opposite sides of said connector, and a connecting portion joining the forward ends of said legs and disposed above the cam surface of said connector, said connecting portion constituting said cam clement, the generally parallel legs of said spring wire being longitudinally adjustable in said rigid frame portion whereby to adjust the position of said cam element with respect to the cam surface of said connector.

References Cited UNITED STATES PATENTS 2,233,861 3/ 1941 Browning 42-42 2,711,042 6/ 1955 Simmons 42-42 3,142,925 8/ 1964 Miller 42-42 3,280,494 10/ 1966 Heiter 42-42 3,304,643 2/ 1967 Nittler 42--42 BENJAMIN A. BORCHELT, Primary Examiner. 

